The author, David Eller, makes a clever point that I never thought about. Intelligent design suffers from a problem with macrocreation. The theory purports to "explain" how certain features of cells (like its origin) and slightly larger systems (e.g. blood-clotting) can evolve, namely by divine intervention. Only.

But that, of course (even though I had not thought about it) leaves ID with a problem of explaining how speciation and other macroevolutionary events can occur. If they can't by evolution, then does the creator also interfere with processes at a higher level of organization? If not, then are the ID theorists (I'm being generous) admitting that natural evolutionary processes can account for them?

However, Behe and most of the effort of the ID movement is not directed at this level or about these questions. They focus on subspecies, microlevel phenomena, like flagella and eyes. Such explanations constitute a kind of microcreationism — claims about how lower-level, intraspecies systems or parts of systems came into being. Microcreation, then, is entirely comparable to microevolution. But neither is a sufficient theory by itself. Evolution demands macroevolution and creationism demands macrocreationism.

2 comments:

As nutty as it is, I find the "directed panspermia" hypothesis to be far less grating than the YEC position. It's far-fetched and, IMO, hopelessly implausible given the relative ages of the universe and life on Earth (see below)... but it doesn't violate any physical laws, and, for the weakest possible definition of "consistent", it is at least consistent with the fossil record.

In fact, I'll even go so far to say that if the age of the universe were a couple of orders of magnitude further back in time as the origin of life on earth, panspermia might be an almost-reasonable hypothesis to get around the "problem" of abiogenesis. Or would have been a few decades ago, before recent progress in explaining how it might have occurred.

My argument goes thusly: If we believe abiogenesis to be such a rare event that it might have only happened once or twice in the universe, AND the universe was around for hundreds of billions of years before life arose on Earth, it might be more parsimonious to reject the anthropic principle, and instead hypothesize that, rather than being the sole cradle of life, we were just one of any number of unremarkable worlds that got seeded with replicators following a catastrophic event(s) on a previously-life bearing world(s) that sent spores careening through space on the backs of comets.

IMO it's the age of the universe, rather than it's sci-fi far-fetchedness that makes this scenario a non-starter. We are positing that abiogenesis is so rare that it only happened once or twice in the universe, and positing that in a mere 8-9 billion years or so, it occurred at least once somewhere else and a catastrophic event set spores from that planet careening through space and it coincidentally collided with Earth??? The latter two events are so ludicrously unlikely, and yet to make this the more parsimonious explanation, we are positing that abiogenesis is an even less likely event -- and yet the scenario also necessitates abiogenesis occuring with the first couple billion years of the life of the universe!

If your hypothesis allows tens or hundreds of billions of years for the sole instance of abiogenesis to spring up, then I might entertain the notion that the contingent spores-in-space events would be more likely than abiogenesis. But without that kind of time to play with, it's a complete non-starter.

(Yes, I probably devoted way too much mental resources to defeating this nutty hypothesis.. I guess panspermia holds a special place in my heart because, as an impressionable-but-not-at-all-religious high school student, I read Hoyle's book, and, not yet knowing he was a kook, I found the "speciation is caused by extra-terrestrial impacts" (which is in his book) to be a seductively contrarian idea at the time. Too bad it's complete bullocks :D

I'm not sure if Armando Simon is referring to panspermia when he says "numerous meteoritic impacts ... have been the primary cause of speciation through cataclysmic effects in the biosphere". I took it as not meaning that, but he could be. He did not answer me on eSkeptic, did not email me, and i can find nothing more he has written than that abstract.

Pleiotropy comes from the Greek πλείων pleion, meaning "more", and τρέπειν trepein, meaning "to turn, to convert". It designates the occurrence of a single gene affecting multiple traits, and is a hugely important concept in evolutionary biology.

I'm a postdoc at UC Santa Barbara.

All Many aspects of evolution interest me, but my research focus is currently on microbial evolution, adaptive radiation, speciation, fitness landscapes, epistasis, and the influence of genetic architecture on adaptation and speciation.